21-51-00
 ALL  ú ú 05 Page 20 ú Sep 20/87
BOEING PROPRIETARY - Copyright (C) - Unpublished Work - See title page for details.
A

757
MAINTENANCE MANUAL

 (2)  
Function

 (a)  
The air from the condensor has many small droplets of water. As the air flows into the water extractor, the helical vanes cause the air to turn. As the air turns, the centrifugal force pushes the water out to the duct wall (the water is pushed farther out than the air because the water is heavier). In the collector part of the water extractor, the inner shell isolates the air/water near the duct wall. The air can flow through the perforations in the inner shell, but the water cannot. Thus, the water flows through the outer shell and into the sump.

 (b)  
The water in the sump then flows to the water spray nozzle of the ram air cooling system. If the sump becomes full, the water flows overboard through one of the ports to the outer shell. The other port connected to the outer shell supplies water to the sump from the split-duct water separator.

 I.  
Split-Duct Water Separator (Fig. 8)

__________________________
 (1)  
The split-duct water separator removes water from the air that flows from the secondary heat exchanger to the reheater. The water that collects in the split-duct water separator is supplied to the sump in the water extractor.

 J.  
Low Limit Control Valve (Fig. 9)

_______________________
 (1)  
The low-limit-control valve controls the flow of hot air from the primary heat exchanger inlet to the air-cycle-machine turbine outlet. Air that flows through the low limit valve does not go through the air cycle machine. This air is used to prevent ice in the turbine outlet and to prevent an overheat condition of the air cycle machine.

 (2)  
The low-limit-control valve is a 2-inch diameter, pneumatically-control, butterfly valve. It has two differential pressure servo assemblies, an electromagnetic control valve, a pneumatic actuator, a reference pressure regulator, a valve flow section, and a valve position indicator.

 (3)  
Description

 (a)  
The high differential pressure servo assembly

 1)  The high differential pressure servo assembly is divided into three parts; the poppet valve assembly, the pressure regulator assembly, and the air inlet assembly. The three parts are connected by an actuator rod. a) The poppet valve assembly has a valve and a valve seat.
 The valve is attached to the actuator rod. The poppet valve assembly bleeds to the vent restrictor connection and the pressure regulator assembly.
 b)  The pressure regulator assembly has a diaphragm, a spring, and two other bleed ports. The diaphragm is attached to the actuator rod. The diaphragm divides the pressure regulator assembly into two chambers. One chamber bleeds to ambient. The other chamber, which has the spring, bleeds to the pneumatic actuator.
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 21-51-00
 ALL  ú ú 07 Page 21 ú Jan 28/02
BOEING PROPRIETARY - Copyright (C) - Unpublished Work - See title page for details.
CONDENSOR
INLET CONNECTION

CONDENSOROUTLET CONNECTION HIGHPRESSURE
AMBIENTSERVO
VENT
REFERENCE
PRESSURE
REGULATOR

CHAMBER A
POPPET VALVEINLET TRAILINGPROBE PACKOUTLETCONNECTION TURBINE MUFFCONNECTIONSERVO
AMBIENTPOPPET
VENT LOWPRESSURESERVO
ELECTROMAGNETICCONTROL VALVEFLAPPER
SUPPLY
AMBIENT

NOZZLE
VENT

AMBIENT VENT
CLOSED STOP
ADJUSTMENT
VENT
RESTRICTOR

OPENCHAMBER
PNEUMATIC
ACTUATOR

AMBIENT VENT
BUTTERFLYPLATE
OPEN STOP
ADJUSTMENT
OPEN

VISUAL POSITIONINDICATOR CLOSED
Low Limit Control ValveFigure 9
CLOSED STOPLOW LIMIT ADJUSTMENTCONTROL VALVE
SEE APACKOUTLETCONNECTION
PNEUMATIC HOT AIRACTUATOR OUTLET CONDENSORINLETCONNECTION
REFERENCEPRESSUREREGULATOR
VISUAL
POSITION
INDICATOR

CONDENSOROUTLETCONNECTIONOPEN STOP
ADJUSTMENT
HIGH AND LOW
TURBINE MUFFPRESSURE SERVO
CONNECTION

AMBIENTVENT ELECTROMAGNETICCONTROL VALVE
LOW LIMIT CONTROL VALVE
A
A
757
MAINTENANCE MANUAL

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